If I configure a server with an FSFS cache that uses about 50% of available memory and then I use the server so the cache is in use I find that hook scripts fail to run because the fork/exec cannot allocate memory. The user sees:
$ svn mkdir -mm http://localhost:8888/obj/repo/A svn: E165002: Failed to start '/home/pm/sw/subversion/obj/repo/hooks/pre-commit' hook and the apache log contains: [Tue Nov 13 21:14:28 2012] [error] [client ::1] Could not MERGE resource "/obj/repo/!svn/txn/0-1" into "/obj/repo". [409, #0] [Tue Nov 13 21:14:28 2012] [error] [client ::1] An error occurred while committing the transaction. [409, #165002] [Tue Nov 13 21:14:28 2012] [error] [client ::1] Failed to start '/home/pm/sw/subversion/obj/repo/hooks/pre-commit' hook [409, #165002] [Tue Nov 13 21:14:28 2012] [error] [client ::1] Can't start process '/home/pm/sw/subversion/obj/repo/hooks/pre-commit': Cannot allocate memory [409, #12] If I increase the available memory by adding swap the hook script starts. Perhaps we could start up a separate hook script process before allocating the large FSFS cache and then delegate the fork/exec to that smaller process? -- Certified & Supported Apache Subversion Downloads: http://www.wandisco.com/subversion/download
